\begin{equation}
    \begin{aligned}
        x =& x^2 \mqty[a_{11}  & a_{12} \\ a_{21} & a_{22}] =& f(x) \\
        y =& f(y) =& y^2 \\
        z =& f(z) =& z^2
    \end{aligned}
\end{equation}
